This invention relates to the art of dispensing wire and, more particularly to a package for containing and dispensing large quantities of a continuous wire without tangling.
The present invention relates to feeding large quantities of a continuous wire from a container to a welding operation wherein the wire must be fed to the welding operation without tangling or interruption. Such containers are known in the art and are generally shown and described in Cooper U.S. Pat. No. 5,277,314; Cooper U.S. Pat. No. 5,819,934; Chung U.S. Pat. No. 5,746,380; Kawasaki U.S. Pat. No. 4,869,367 and Gelmetti U.S. Pat. No. 5,494,160. These patents are incorporated by reference herein as background information illustrating packages for containing and dispensing large quantities of wire. Further, these patents illustrate the importance of controlling the wire as it is being dispensed from the package to prevent tangling.
Seufer U.S. Pat. No. 5,816,466 illustrates the interaction between the wire package and the wire feeder which is a part of the welding apparatus and is incorporated by reference herein as background information.
The present invention is particularly applicable for use in connection with welding wire and, therefore, the invention will be described with particular reference to a package containing a large quantity of welding wire stored therein as a coil containing many convolutions formed into layers. However, the invention has broader applications and may be used with any type of wire or other wire-like materials.
It is, of course, well known that welding is an effective method of joining metal components. Further, it is well known that utilizing a welding wire as a consumable electrode in the welding process enhances the weld. Accordingly, it is desirous to package welding wire so that it can be cost effectively utilized. Furthermore, welding applications wherein large quantities of welding wire are consumed necessitate welding wire packages which contain large quantities of a continuous welding wire. Accordingly, large welding wire packages have been created for these applications which allow for a significant amount of welding run time before the operation must be shut down to restring a new package of welding wire. This is particularly important for automated or semi-automated welding operations.
In order to work in connection with the wire feeder of the welder, the welding wire must be dispensed in a non-twisted, non-distorted and non-canted condition which produces a more uniform weld without human attention. It is well known that wire has a tendency to seek a predetermined natural condition which can adversely affect the welding process. Accordingly the wire must be sufficiently controlled by the interaction between the welding wire package and the wire feeder. To help in this respect, the manufacturers of welding wire produce a wire having natural cast wherein if a segment of the wire was laid on the floor, the natural shape of the wire would be essentially a straight line; however, in order to package large quantities of the wire, the wire is coiled into the package which can produce a significant amount of wire distortion and tangling as the wire is dispensed from the package. As a result, it is important to control the payout of the wire from the package in order to reduce twisting, tangling or canting of the welding wire. This condition is worsened with larger welding wire packages which are favored in automated or semi-automated welding.
The payout portion of the welding wire package helps control the outflow of the welding wire from the package without introducing additional distortions in the welding wire to ensure the desired continuous smooth flow of welding wire. Both tangling or breaking of the welding wire can cause significant down time while the damaged wire is removed and the wire is re-fed into the wire feeder. In this respect, when the welding wire is payed out of the welding wire package, it is important that the memory or natural cast of the wire be controlled so that the wire does not tangle. The welding wire package comprises a coil of wire having many layers of wire convolutions laid from the bottom to the top of the package. These convolutions include an inner diameter and an outer diameter wherein the inner diameter is substantially smaller than the width or outer diameter of the welding wire package. The memory or natural cast of the wire causes a constant force in the convolutions of wire which is directed outwardly such that the diameter of the convolutions is under the influence of force to widen. The walls of the wire welding package prevent such widening. However, when the welding wire payes out of the package, the walls of the package loose their influence on the wire and the wire is forced toward its natural cast. This causes the portion of the wire which is being withdrawn from the package to loosen and tend to spring back into the package thereby interfering and possibly becoming tangled with other convolutions of wire. In addition to the natural cast, the wire can have a certain amount of twist which causes the convolutions of welding wire in the coil to spring upwardly.
Retainer rings have been utilized to control the spring back and upward springing of the wire along with controlling the payout of the wire. This is accomplished by positioning the retainer ring on the top of the coil and forcing it downwardly against the natural springing effect of the welding wire. The downward force is either the result of the weight of the retainer ring or a separate force producing member such as an elastic band connected between the retainer ring and the bottom of the package. Further, the optimal downward force during the shipment of the package is different than the optimal downward force for the payout of the welding wire. Accordingly, while elastic bands or other straps are utilized to maintain the position of the retainer ring during shipping, the weight of the retainer ring can be used to maintain the position of the retainer ring relative to the wire coils during payout. With respect to managing the outward flow of wire, or payout, the retainer ring""s position on the top of the wire coil holds the upper layers of the convolutions in place as the wire is withdrawn one convolution at a time. In addition, the retainer ring includes an inwardly facing edge which controls the payout of the wire. In this respect, the wire is pulled from the center of the retainer ring and engages the inwardly facing edge. The retainer ring further includes a mechanism to prevent the wire from springing around the outside of the retainer ring. Prior art retainer rings utilize resilient members which tightly engage the inner surface of the package to protect the outer convolutions of the welding wire coil and prevent the wire from springing around the outside of the retainer ring. However, by having frictional engagement between the retainer ring and the inner container walls drag is introduced which adversely reduces the downward force of the retainer ring on the wire coil can and can adversely jam the retainer ring above the wire coil, thereby reducing its control on the wire payout. In order to overcome the retainer ring drag, the weight of the retainer ring must be increased or separate weight must be utilized.
The ability to inexpensively dispose of the welding wire package is also important. While rigid packages can advantageously reduce the tendency of coil shifting within the package during shipment and use, and enhance the stackability of the package, they can be difficult and expensive to dispose of. In welding operations which consume significant quantities of welding wire, stackability and movement characteristics of the full package along with the ability to dispose of the empty package can all play a significant roll in the support operations for the welding process.
In accordance with the present invention, provided is a welding wire package is provided which includes a retainer ring that interacts with the inner liner of the welding wire package to control the payout of the welding wire and which ring and package are easily disposed of once the welding wire of the package has been consumed. In this respect, a package in accordance with the present invention includes a retainer ring conforming to the inner walls of the package and including portions that extend radially beyond the outer diameter of the wire coil convolutions for minimizing or eliminating the frictional interengagement between the retainer ring and the inner walls of the package. By including portions which extend beyond the outer diameter of the wire coil, the retainer ring advantageously prevents convolutions from springing outside of the ring without necessitating excessive frictional interengagement between the retainer ring and the inner walls of the package.
Preferably, the retainer ring according to the present invention is used in connection with an inner liner having an octagonal cross-sectional configuration, wherein the extending portions of the retainer ring extend beyond the outer diameter of the wire coil into the corners of the octagonal liner. By extending beyond the outer diameter of the wire coil, frictional interengagement with the inner liner is not required and the retainer ring is allowed to freely descend downwardly within the inner liner as the wire is payed out of the package. The lack of frictional engagement allows a lighter and a more disposable retainer ring to be utilized which is inexpensive to manufacture while still being effective in controlling the payout of the welding wire. When used in connection with a disposable cardboard-style box package, the arrangement makes disposal of the packaging after use less costly. This is especially advantageous in high volume welding processes such as for automated or semi-automated welding.
Another aspect of the present invention is that the engagement points between the wire coil and the inner liner are spaced from the engagement points between the retainer ring and the inner liner. Therefore, the forces produced by the convolutions of the coiled wire are controlled by the inner liner and are spaced from the extensions of the retainer ring which further prevents the convolution from passing outside the ring. In this respect, whether an octagonal liner is used, or merely a square box, or even a cylindrical container with supports, the outer diameter of the welding wire interengages with the inner surfaces of the welding wire package at predetermined points equally spaced within the welding wire package. With respect to octagonal inner liners, the outer diameters of the convolutions interengage the vertically extending planar walls of the inner liner generally at their centers. Conversely, the retainer ring extensions engage the inner liner at one or more of the corners between the vertically extending walls. As a result, even though the wire can cause deformation of the central portions of the vertically extending inner liner wall, the extensions on the retainer ring are spaced therefrom and are not affected. Therefore, the retainer ring according to the present invention does not have to interengage with the inner liner to such a degree to account for the potential deformation caused thereto by the wire coil which further reduces the friction therebetween. In addition, by including an inwardly extending edge portion between the extensions, friction is further reduced and the position of the retainer ring is not influenced by the deformation of the liner caused by the outward force produced by the wire coil.
With reference to a square or a circular liner arrangement, the same result can be achieved. In this respect, the retainer ring for a square inner liner configuration, includes extensions which extend into the four corners of the square liner, thereby extending beyond the outer diameter of the wire coil. A cylindrical inner liner or package which includes a plurality of vertically extending support members to retain the outer convolutions of the wire coil utilizes a retainer ring which extends beyond the support members and thus the outer surface of the wire coil.
The primary object of the present invention is the provision of a retainer ring for a wire coil package which allows the continuous and uninterrupted payout of a welding wire from the package smoothly and without tangling.
Another object is the provision of a welding wire package of the foregoing character that can be easily transported and otherwise manipulated into an operating position.
Still another object is the provision of a retainer ring for a welding wire package of the foregoing character which is lightweight and disposable and which provides continuous and smooth payout of the welding wire.
A further object is the provision of welding wire packaging of the foregoing character wherein more components can be easily and inexpensively disposed of after use.
Yet a further object is the provision of a welding wire package of the foregoing character that utilizes a retainer ring which extends radially beyond the outer diameter of a wire coil to prevent the convolutions of the wire coil from escaping beyond the outer edge of the retainer ring without the need of frictional interengagement with the inner surface of the welding wire package.
Another object is the provision of a welding wire package of the foregoing character which utilizes components that are economical to manufacture, easy to use in the field and protect the welding wire.